The External Shape of Human γ GI Immunoglobulin from Crystal Sections

Author(s):  
L. W. Labaw

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

1995 ◽  
Vol 48 (9) ◽  
pp. 1659 ◽  
Author(s):  
VJ Hall ◽  
ERT Tiekink

The reaction of Ph3SnCl and Cy2P(O)C(S)N(H)Me yields the air-stable adduct Ph3Sn[Cy2P(O)-C(S)N(H)Me]Cl which features a trigonal bipyramidal tin atom geometry with a chlorine atom [Sn-Cl 2.4236(9)Ǻ] and an oxygen atom [Sn-O 2.523(2)Ǻ], derived from a monodentate phosphinyl(thioformamide) ligand, occupying the axial positions. The pale-yellow crystals are monoclinic, space group P21/c with unit cell dimensions a 10.050(1), b 16.501(1), c 19.273(1) Ǻ, β 102.12(1)°, Z 4; the structure was refined to final R 0.031 by using 5384 reflections.


1977 ◽  
Vol 55 (1) ◽  
pp. 111-114 ◽  
Author(s):  
Lillian Y. Y. Chan ◽  
E. E. Isaacs ◽  
W. A. G. Graham

Reaction of [n-Bu4N]2[Re4(CO)16] with AgBF4 in acetonitrile affords the compound [(CH3CN)3Re(CO)3][BF4]. The latter crystallizes in monoclinic space group P21/c with unit cell dimensions a = 11.021(5) Å, b = 11.136(5) Å, c = 12.980(6) Å, β = 96.906(25)°, and four molecules per unit cell. Data were collected by counter methods and the structure was refined using least-squares procedures to give R = 0.041. The rhenium cation is approximately octahedrally coordinated by six facially arranged ligands. The mean rhenium–nitrogen distance is 2.13 Å, and the mean rhenium–nitrogen–carbon angle in the coordinated acetonitrile is 174.7°.


1995 ◽  
Vol 48 (4) ◽  
pp. 757 ◽  
Author(s):  
G Siasios ◽  
ERT Tiekink

The reaction of [AuCl4]- with Cy2P(O)C(S)N(H)Me in the presence of thiodiglycol affords the air-stable adduct Au[Cy2P(O)C(S)N(H)Me] Cl which features a linear gold atom geometry defined by a chloride atom and a sulfur atom derived from a monodentate thioformamide ligand. The pale-green crystals are monoclinic, space group P21, with unit cell dimensions a 18.507(4), b 12.204(2), c 18.513(6) Ǻ, β 117.69(2)°, Z 8; the structure was refined to final R 0.042, 4106 reflections being used.


1988 ◽  
Vol 41 (4) ◽  
pp. 597 ◽  
Author(s):  
MI Bruce ◽  
MP Cifuentes ◽  
KR Grundy ◽  
MJ Liddell ◽  
MR Snow ◽  
...  

An improved, one-pot synthesis is reported for the [Ru (dppm -P)(dppm -P, P′)(η-C5H5)]+ cation as its BF4- salt. The crystal structure of [Ru ( dppm - P)( dppm -P,P′)(η-C5H5)]+, obtained as the mixed PF6-/PO2F2- salt, has also been determined. There are few differences in dimensions between the mono- and bi-dentate dppm ligands; chelation sharply reduces the P-CH2-P angle, and one phenyl group on each phosphorus is bent away from the metal. Crystals are monoclinic, space group C2/c with unit cell dimensions a 21.743(3), b 23.594(3), c 21.352(3)Ǻ, β 110.17(1) and Z 8. The structure was refined by a full-matrix least-squares procedure to final R 0.078 and Rw 0.087 for 4490 reflections with I > 2.5σ(I).


1996 ◽  
Vol 11 (4) ◽  
pp. 301-304
Author(s):  
Héctor Novoa de Armas ◽  
Rolando González Hernández ◽  
José Antonio Henao Martínez ◽  
Ramón Poméz Hernández

p-nitrophenol, C6H5NO3, and disophenol, C6H3I2NO3, have been investigated by means of X-ray powder diffraction. The unit cell dimensions were determined from diffractometer methods, using monochromatic CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found for p-nitrophenol was a=6.159(2) Å, b=8.890(2) Å, c=11.770(2) Å, β=103.04(2)°, Z=4, space group P21 or P2l/m, Dx=1.469 Mg/m3. The monoclinic cell found for disophenol has the dimensions a=8.886(1) Å, b=14.088(2) Å, c=8.521(1) Å, β=91.11(1)°, Z=4, space group P2, P2, Pm or P2/m, Dx=2.438 Mg/m3.


1999 ◽  
Vol 55 (2) ◽  
pp. 539-541
Author(s):  
Palangpon Kongsaeree ◽  
Jun Liang ◽  
Roy A. Jensen ◽  
Jon Clardy

The title protein has been crystallized in a new crystal form. The crystals belong to the cubic space group P4132 (or P4332) with unit-cell dimensions a = b = c = 126.1 Å at 100 K and typically diffract beyond 1.6 Å at the Cornell High Energy Synchotron Source (CHESS) A1 beamline.


1992 ◽  
Vol 45 (11) ◽  
pp. 1933 ◽  
Author(s):  
PR Traill ◽  
AG Wedd ◽  
ERT Tiekink

The characterization of two MoVI complexes, cis -[MoO2(2-pymS)2] and cis -[MoO2(2-pyS)2] (where 2-pymSH is pyrimidine-2-thiol and 2-pySH is pyridine-2-thiol), and their reaction with Ph3P are reported. The X-ray structure of cis -[MoO2(2-pymS)2] shows the molybdenum atom to exist in a distorted octahedral geometry defined by two mutually cis oxygen atoms and two chelating 2-pymS ligands so that the two sulfur atoms occupy approximate trans positions. Crystals of cis -[MoO2(2-pymS)2] are monoclinic, space group P 21/n, with unit cell dimensions: a 9.301(3), b 12.121(2), c 11.303(3) �, β 112.62(3)�, V 1176.3 �3, Z 4. The structure was refined by a full-matrix least-squares procedure to R 0.067 for 1858 reflections with I ≥ 2.5 (I).


1976 ◽  
Vol 31 (9) ◽  
pp. 1175-1178 ◽  
Author(s):  
Kurt Walenta

A new compound having the same composition as zircon, ZrSiO4, but differing from it in its structure has been obtained by heating zircon particles to a temperature of 5000 to 10000°K. According to X-ray powder diffraction data the structure and within limits of error also the unit-cell dimensions are identical with that of monoclinic baddeleyite, ZrO2. This suggests that the baddeleyite lattice can not only accommodate 10 molecular % SiO2 as is already known for some time, but substantially more, unless it is assumed that some kind of submicroscopic exsolution of amorphous SiO2 has taken place.


1987 ◽  
Vol 65 (12) ◽  
pp. 2830-2833 ◽  
Author(s):  
David M. McKinnon ◽  
Peter D. Clark ◽  
Robert O. Martin ◽  
Louis T. J. Delbaere ◽  
J. Wilson Quail

3,5-Diphenyl-1,2-dithiolium-4-olate (1) reacts with aniline to form 1-phenylimino-2-phenylamino-3-phenylindene (3a). Under suitable conditions, 6-phenylbenzo[b]indeno[1,2-e]-1,2-thiazine is also formed. These structures are confirmed by alternative syntheses. The molecular structure of 3a has been determined by single crystal X-ray diffraction. Compound 3a crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 20.777(3) Å, b = 6.130(3) Å, c = 31.327(3) Å, 3 = 99.59(1)°, and Z = 8. The structure was solved by direct methods and refined by least squares to a final R = 0.055. The molecular structure of 3a shows the three phenyl containing substituents to have the planes of their ring systems tilted between 40° and 60° from the plane of the indene system due to steric repulsions.


1976 ◽  
Vol 54 (17) ◽  
pp. 2723-2732 ◽  
Author(s):  
Simon E. V. Phillips ◽  
James Trotter

The structures of the title compounds have been determined by three dimensional X-ray crystal structure analysis.Crystals of anhydrous phenacylkojate are monoclinic, space group P21/c, with unit cell dimensions a = 9.087(4), b = 11.764(3), c = 12.714(4) Å, β = 116.57(2)°, Z = 4. The structure was solved by direct methods and refined by full-matrix least-squares to R = 0.044 for 1225 independent diffractometer observations. The crystal structure is held together by hydrogen bonding between carbonyl and hydroxyl groups and [Formula: see text] interactions.Crystals of the sodium chloride complex are monoclinic, space group C2/c, with unit cell dimensions a = 11.3714(6), b = 15.796(1), c = 14.487(1) Å, β = 97.241(5)°, Z = 4. The structure was solved by heavy atom and Fourier methods and comparison with the previously determined structure of the potassium iodide complex. It was refined to R = 0.040 for 1670 independent diffractometer observations. The structure closely resembles that of the potassium iodide complex (P21/n), but in C2/c, the alkali metal ion being eight co-ordinate in each. Na+—O distances are in the range 2.558–2.674 Å and the [Formula: see text] hydrogen bonded distance is 3.266 Å.


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